Auto jack



July 29, 194']. E. J. cHAMBER AUTO JACK Fi1ed Sept.'26. 1944 6 Sheets-Sheet l July 29, 1947. E. J. CHAMBERS AUTO JACK Filed Sept. 26, 1944 6 sneaks-sheet :s

@Q I I 0Q g jiwenior Edwdrd J Ckamers July 29,1947;

E. J, CHAMBERS v 2,424,741

(AUTO JACK 6 Sheets-Sheet 5 Filed Sept; 26. 1944 14 7 512, f5 6: v A WW/ .59

Invenaofi fidwa zgdkamfiers aom July 29, 1947. E. J. CHAMBERS 4 AUTO JACK Filed Sept. 26, 1944 6 Sheets-Sheet 6 Jnuenlor l'dwa gddkambers Patented July 29, 1947 AUTO JACK Edward J. Chambers, Chicago, 111., assignor of forty-nine per cent to John Br'eland Whigam,

Chicago, Ill.

Application September 26, 1944, Serial No. 555,818

19. Claims. (Cl. 254-86) My invention relates to multiple fluid lack.

structure used in association with a vehicle chassis, or mounting, adapting the same to be raised at four individual points adjacent its wheels, or permitting the simultaneous raising of the entire automobile by virtue of the jack struc ture adjacent each wheel, and being further provided with mechanism adapted to return all or as many of the said four lacks that are in extended position, to normal or inoperative position.

One object of my invention is to provide a jack structure which is articulately secured, and is adapted to be rotated thru an angular movement approximately, and substantially 90, then the 'jackstructure is adapted to be extended so as to furnish lift, or lifting movement, to a vehicle to which it may be attached, the said Jack structure being further adapted to 'belretracted, and to be rotated thru an angle of substantially 90 to return it to normal or horizontal position.

Another object of my invention is to provide a fluid operated Jack means which is provided with snap locking means in extended or contractedposition of the piston or foot support structure of the said Jack means,

Another object of my invention is to provide in a jack structure of the aforementioned character, rack and reversablepawl means adapted to safeguard the upward or downward movement of the extensible means of the said jack structure, preventing accidental drop of the load being supported, if for some reason the fluid operative mechanism of the jack structure should become inefiective or inoperative.

Another object of my invention is to provide electro-magnetic control means associated with.

fluid pressure means to automatically operate an individual jack structure to extended or operative position.

Another object of my invention is to provide a unitary electro-magnetic control associated with fluid pressure means adapted to retract one or more of the jack structures which had prior' thereto been extended or elongated in order to support a load in raised position.

Another object of my invention is'to provide fluid pressure operated keeper means associated with retaining means provided on the aforementioned type of jack structure which will retain the said Jack structure in inoperative position or in normal position.

Another object of my invention is to provide electro-magnetic means cooperating with fluid pressure means, which will first operate valve means connecting the fluid conduit leading from the said jack means to the source of supply and cause the said fluid means to operate the retaining means freeing'it from the keeper structure, then p'ermitthe fluid pressure-to be built up so as to cause and produce movement of a rack structure in mesh with a pinion structure connected to the, jack body, causing the same to rotate thru an angle of substantially 90; the fluid pressure then being further built up in a valve means so as to shift the passage connection or conduit connection causing th fluid pressure to operate the piston structure within the said body causing the same to be moved downwardly, thus lifting the load supported thereon; and, simultaneously, or prior to the downward movement of the said jack body, the fluid being so controlled as to cause the disengagement of snap locking means enabling the piston structure to be extended downwardly and causing the same to be locked in fully extended position by the said locking means. A second electro-magnetically controlled valve means is also associated I with the said mechanism and operates independently from the said first mentioned electro-magnetically controlled valve means for reversing the action of extending the said jack means to support a load, in other words, causing the retraction thereof in the following manner; the pressure being first directed so as to cause the said locking means to be disengaged freeing the piston for upward movement or travel, the pressure then being built up suiflciently, exerting it below the piston and forcing the same upward. When the piston reaches its upward position, the pressure continues to build up and thus causes communication between another conduit which will feed' the pressure into the said rack and pinion mechanism causing the rack to be reversed in directional movement, which in turn will result in. causing the jack structure to be rotated thru'the angular movement it had originally been motivated, returning it to normal, or substantially,

horizontal position, simultaneously therewith,

chassis, wheels, and driving means in phantom, and the jack structure, comprising my invention, in full lines showing the relative connection for proper association and cooperation of the prime mover means embodied in a vehicle structure to operate the needed mechanism to furnish the necessary fluid pressure required to operate the mechanism of the jack structure comprising my invention, as will hereinafter be more clearly elucidated.

Fig. 2 is an enlarged fragmentary front view of a jack structure comprising my invention in extended position, preferably, that jack structure associated with the front support at the front wheels of an automobile.

Fig. 3 is a diagrammatic showing of an automobile dash structure indicating generally the electro-magnetic circuit utilized in cooperation with the fluid pressure system for operating my invention.

Fig. 4 is an enlarged view partly in cross-section showing the details of the elemental structure of one of the jack assemblies, showing also in dotted lines the arcuate movement thru which it is rotated to bring it to normal or inoperative position.

Fig. 5 is a longitudinal cross-sectional view taken on Figure 4 showing that fragmentary portion of the jack body which is provided with stop portions so as to definitely limit the arcuate or angular movement thereof,

Fig. 6 is a fragmentary side view of the lower portion of Figure 4 showing the detailed elemental structure of the mechanical safety and fool-proofing means which will prevent accidental disturbance of the extensibility or retractability of the jack structure comprising my invention in the event of failure of the fluid pressure system, in which event the jack structure will remain in mechanically locked engagement at the particular point where the said failure occurs causing no damage to the load supported thereby.

Fig. '1 indicates a longitudinal cross-sectional view taken substantially on'the line 1-1 of Figure 4, with the exception that in this view the foot supporting structure of the jack is shown in extended position.

Fig. '8 is a transversal cross-sectional view on the line 8-8 of Figure 7.

Fig. 91s a transversal cross-sectional view taken on the line 9-9 of Figure '1.

Fig. 10 is a transversal cross-sectional view taken, substantially, on the line Ill-III of Figure '1.

Fig. 11 is a transversal cross-sectional view taken, substantially, on the line II--II of Figure 7.

Fig. 12 is a transversal cross-sectional view taken, substantially. on the line I2-I2 of Figure 1.

Fig. 13 is a diagrammatic, or schematic, view showing the arrangement of the particular portion of my fluid pressure operated jack system to which are attributable the results produced, related in the foregoing preamble of the description where the objects of .the invention are enumerated.

Referring to Figure 1, the chassis of an automobile is, generally, designated IE to which are secured in horizontal normal position the lack structures I5 adjacent each of the wheels I 6 of the said automobile. The automobile structure is provided with suitable motive power means and a transmission shaft I3 connected to the differential gearing I1. The transmission shaft at a suitent inautomobiles is indicated thereon. It conable point is provided-with chained transmission means 33 or other suitable transmission means, which will operate the pump or compressor connected by virtue of conduit to a suitable storage tank 3!. The said storage tank i provided with a safety or blowofl' valve I31 to release pressure that may accumulate beyond the safety factor of the container 35, causing such excess air pressure to be exhausted and thus maintain within the storage tank 38 suitable pressure at all times for operating the jack mechanism as will be hereinafter more clearly explained. The stor age tank 38 is connected by virtue ofconduit 31 to another fluid pressure feed tank 38 which is connected to the various electro-magnetic valve structures secured to the dash I I of the automobile, and which are used for jointly or individually operating the individual jack means to exten the same and lift the load, or for retraction thereof relieving or releasing the load to rest on its support. I

In Figure 2, where the chassis structure I5 is indicated, the necessary knee action usually pressists of the cap I30 and the bracket I32 confining therebetween a proper resilient means or spring means I3I, the two being interconnected by the yoke member I29 which is provided with suitable bearings in order to articulately receive the support I35. The said supp rt I35 has an extension I21 articulatelysecured to the tie rod I28, which in turn is connected thru proper gearing to the steering wheel of an automobile; the tapered shaft structure I33 is integral with the bracket I35 and the two are'fulcrumed by virtue of the pivot I23; the shaft I33 being adapted to receive the hub of a wheel, and the reduced threaded extension thereof designated I34'equipped to re-. ceive the necessary locking means to maintain the front wheel for free rotation on the said shaft I33. The jack body is, generally, designated 98 and the piston extension thereof is designated 89. The said piston operates reciprocally therein, 1. e. outwardly when extended, and inwardly when the mechanism is to be retracted.

In Figure 3, the automobile body, generally, comprising a dash I4 connected to the hood arrangement or body proper is also equipped with the customary windshield structure Ill. view also indicates how the fluid pressure feed tank 38 is connected by virtue of conduit 31 to the storage tank 36, then in turn to the compressor 3|.

The electrical circuit indicates one of the electro-magnetic valve means operated by the switch I9 which happens to be the switch for returning the jack to normal position. The four electromagnetic switches 23 are so arranged with the fluid pressure as to cause extension of the lock means, or lift of the load by the extension thereof. It can be seen in this view that the switch means I9 is connected to the valve means 29 and is connected in series by virtue of electrical conduits2l and 22 to a source of electric supply 20. The switches 23 are connected in parallel in the same circuit so that any one of the said switches 23 can be operated independently to close the circuit thereof, the said switches being in parallel relation, hence it it is desired to raise the four jacks simultaneously, the four switches would be closed simultaneously. However, the entire system is set for retracting any or all of the jack structures by virtue of the single electro-magnetic' control I3,

The Jack structure, generally, comprises a body This . tion I50, whereas the shoulder I52 abuts the shoulder II when the device is retracted or in horizontal and inoperative position.

' As can be seen,,to the bracket'structure I48, an auxiliary bracket is secured which includes the cylindrical structure 49 having the substantially semi-circular housing portion 99 for confining a segmental gear I44 which cooperates with a rack 53 to the end of which are secured- Diston structures I42 held in place by virtue of screws I43.

The fluid conduit 5I is connected to the elethe rack is free to move upwardly-when the lever I58 is in the dotted position indicated, and the tooth I63 is in engagement with the rack I56, it can be seen how the tooth I68'will allow the rack to move upwardly but prevent it from moving downwardly. So thatif failure of fluid pressure should occur at any time. the said positive automatic mechanical means will fool-prooi the entire structure and prevent accidental damage to any portion or the load being supported thereby. When the rack I56 moves upwardly then the pin I61 will trip the lever I58 changing its position i'rom dotted lines shown in Figure 6 to full lines to repeat the cycle.

It is also to be noted that the jack structures proper are provided with a portion 68 (see Figure 4) which contains the retaining means II which co-acts with the keeper means 69, attached to some static portion of the chassis I5, so that the inoperative position, or in locked position when ment 49 to cause the fluid pressure to actuate, or 1 to operate, within the compartment I6 of the tubular structure 49, the said rack 53 in one direction,,whereas the conduit 48 is disposed to cause the said rack 53when the pressure is fed in from the opposite end to cause the rack 53 to return to normal position. The said rack 53, being in mesh with the segmental gear I44, mounted on shaft I45 and secured by key I46, will cause the same to be rotated thru an arcuate distance equivalent to that permitted .by the confines of the shoulders I53 and I54 abutting one another or by virtue of the shoulder I53 abutting the shoulder I5I showing the two extreme positions of angular or arcuate operation. The securing cylindrical portion I4'I acts as suitable bearing for the Jack body 98 for angular rotation thereof.

In Figures 4 and 6 the means for making safe the operation of the jack means is also indicated. The said jack means is provided with extensions I55 into which are driven pin supports I60 furnishing anchorage to the springs I59 which in turn are connected to a lever I58 fulcrumed at I 6i and having a. suitable extension for retaining the opposite ends of the springs I59. The said levers I58 are integrally secured to the duplex pawl arrangement I62 having the terminal portions I63 of such angular configuration as to engage the teeth I65 of. the rack I56, which is guided by the extensions I69 provided on the body 98 and secured firmly in place by virtue of pins I66 to the equalizer foot support means I03.

The foot I05 is caused to be moved downward as shown by the position indicated in Figure 6 in full lines, indicating that the said rack I56 is free to move downwardly, the rack I56 being in snap engagement with the tooth I64. When the travel has been about'completed the pin I51 will be caused to engage the lever I58 causing the same to move downward. When it has passed the axis of the supporting pin I60 the said lever will snap downwardly and thus cause the portion I63 to .becomeengaged with the teeth I 65. whereas the portion I64 will become disengaged with respect to the teeth I65 as indicated by'the dotted position in Figure 6. Now, if we consider it can be seen how the rack is free to move downwardlyybut will not be free to move up-- wardly, it being arrested by the toothed portion the jack structure is not being used.

For a clearer explanation of the jack structure, Iwill proceed to elucidate further the elemental structure thereof. It should be noted that the same is comprised of a body 98, as here-- tofore mentioned, which is bored out in order to receive the piston structure 94 having the customary piston ring means 95 on top and on bottom to furnish proper pressure sealing means therefor, preventing leakage. The said piston structure is also provided with shoulder means I25 and I24 so as to prevent the pistons from contacting the top or bottom cavity or housing within the body 98, for reasons later to be elucidated, namely to provide a small area for fluid pressure to apply its initial action to the movement of the said Dis: ton upwardly or downwardly as the case may necessitate.

The piston structure is provided with a rod guide 89 which is provided with looking recesses 90 at the top thereof and the h shaped passage (see Figure 7) comprised of an opening 9i and I tioned h passage is indicated and is comprised of the thru recess 8i, and the partially drilled opening I9, interconnected by means of the recess' 80. The lower portion of the piston rod 89 is suitably threaded as indicated at I04 in order to pass through the lower plug structure IOI which is provided with an extension I02 and an angular shoulder portion so as to locate the equalizer foot support means I03 which is secured to the thread I04 in looking engagement.

The foot element I05 is provided with a domeshaped section which has a bore Ill and is held in place by the spherically-shaped washer I01 and the screw I08. The recess I'II provides equalization to the foot element I 05 while the teeth I06 grip the pavement, furnishing equalization in the event the pavement should not be perfectly horizontal, or if it be irregular on its surface.

It can be seen also that the body 98 is provided with an extension 68 in which is housed a retaining means II which coacts with the slotted or shoulder portion 10 of thekeeper means 69. The retainer II is provided with an enlarged head I2 held normally in extended position by the spring13. The vent 14 is provided so as to per-' mit evacuation of the air within the confines of I64 of the duplex pawl I62. Conversely when the housing wherein the head I2 operates when the said head is being moved upwardly so as to discngagei the retaining means 1! from the keeper 69.

The piston rod 89 is likewise provided with two indentations designated 88 for engagement by the extensions 81 of the locking means 83. The said locking means is provided with a suitable recess 34 so as to receive compactly the springs I12. .The vents 83 and 86 are provided thru the jack body 38 and the screwplugs I08 in order to permit expulsion of the air within the confines surrounding the springs I12 when the fluid pressure means causes the plungers 83 to be retracted for removing or releasing from engagement with the indentations 81 or 90 at either the retracted position preparatory for extension, or in the extended position preparatory to retraction. Each cylinder is also provided with valve portions 58 and III, and also with electromagnetically operable valve portions 4| and 29.

The structural arrangement of the valve portions 58 comprises a housing portion in which is confined a valve plunger moving therein having the enlarged shoulder portion62, and undercut portions I13 and I14; the plunger is also provided with a bored opening 64 communicating with a vent 55, whereas the body or housing 58 is also provided with openings to receive the conduits 66, 18, 96, 56 and 51. The spring 8| is provided in order to maintain the valve plunger 62 in the position indicated in full lines in Figure '13. Associated with this valve-like extension 58 another member designated 4| is provided which has a valve body with two enlarged sections 45 and a reduced intermediate section 48. The said body has also a stem 26, integral with the core of the electro-magnetic solenoid 25, which is connected to the switch 23 by means of electrical conduits I38, 22 and 2| in series with the source of supply of electrical energy 20. To the said body 4| the pressure feed I36 coming from the fluid reservoir 38 is connected, and also the conduit 41 is connected thereto; vent openings 43 and are provided for purposes which will hereinaiter be more clearly elucidated in the operation of this device.

The fluid pressure system comprised of the unit portions 4| and 58 connected to the rack and pinion means 52 and I44, also is connected to fluid pressure means to simultaneously or consecutively operate the retainer 1| and the locking means 83. The control of the fluid means within that conduit or fluid pressure circuit is such as to control the unlocking or the release of the retainer means 1| from the keeper means 10, also to release the locking means 81 to permit the arcuate rotation of the .jack body'98, and ultimately the extension.

of the piston structure 94 so as to relieve a load from the surface on which it is supported.

In order to complete the cycle of operation, and retract the extended pistons, the following structure is utilized. The portion 23 is connected to the conduits 30 from each jack structure also a valve structure 1 in co-action with an electromagnetic solenold 24 is provided which is connected in parallel to the electrical circuit indicated by conduits 2| and 22 by virtue of switch liiandthe electrical contacts I33 and I40. The structure 29 is similar to that indicated for the valve structure 4|, namely, a duplex piston structure 23, having a relieved intermediate body portion 33, and terminating in a stem 21 which is integral with the core of the electro-magnetic solenoid 24. The portion 23 is provided with an opening 3| an opening for connection to the conduits 33, and also an opening ior connection to the conduit 32 which in turn is connected to the conduit I18 providing fluid pressure for operating thevalve portion 1 when the electro-magnetic solenoid 24 is energized.

In order to reverse the operation of the Jack structure, it is mandatory to first release the locking means 81 from the indentations 83, then to build up the pressure to cause the jack to be retracted to its uppermost position, then to continue to build up the pressure so as to direct it toward the conflnes oi the housing 5|! below the piston 52 operating the rack to rotate the pinion in mesh therewith. The preceding operation will cause the jack structure to be rotated back to,

to force valve H9 to compress the spring I2I and to bring about alignment between conduits H5 and 5|, at the same time causing the venting orifice I23 to'register with the passage I I6. The undercut I18 permits communication of the chamber 50 with exhaust or vent I I8 thru conduit 5| to permit rack piston 53 to move downwardly.

Complete cycle of op eration having special reference to Figure 13 In Figure 13, the complete electro-magnetic valve arrangement for cyclic operation is indicated as embodied in the combination of the solenoids 24 and 25 as heretofore explained, co-acting with the valve structures 4| and 29, the valve structures 58 and 1 together with the plunger structures 83 and the locking structures 81, as

well as the keeper 69 cooperating with the retainer structure 1|.

The operation of the co-ordinated mechanism illustrated in Figure 13 is as follows: The compressor 34 is operated by the chainor belt drive 33 causing the same to provide sumcient air pressure in the intermediate storage tank 33 which is provided with the proper blow-off, or safety valve I31, thus providing a uniform pressure in the distributing cylinder 38. Thesaid cylinder 38 is connected to the conduit I10 and to the four conduits I36 all of which are connected to electromagnetic valve structures 4| similar to the one indicated. It is to be noted, when the switch 23 is actuated so as to complete the circuit of the conductors 2 I, 22 and I38, the circuit being closed, the electro-magnetic solenoid 25 becomes energized, its core being attached to the stem 23 of the valve head 45, will cause the same to be moved in a direction to the right of the full lines indicated in Figure 13 thus closing the vent 23 at the same time compressing the spring 42 and providing communication between the conduit I38 and the conduit 41 thru the chamber of the valve body 4|.

- It is also to be noted that the fluid pressure will then be distributed in two branches into conduits 51 and 48. To begin with. the fluid pressure will feed thru the conduit 51 which is connected to the valve structure 53 and which permits communication with the conduit 56 by virtue of the undercut shoulder I13 on the valve stem 62, so that the fluid pressure being directed thru the conduits 63 and 61 will be fed into the chamber of the extension 88 and the pressure building up sumcientlywill cause the head 12 to be raised surface.

' move to the right expelling whatever air is in the confines of chamber 69 thru the vent 59.

When the valve stem has moved completely to the right compressing the spring 6|, the conduit 51 willbe caused to communicate with the conduit 18 feeding into the inlet 19 and thru the intermediate connection 89 into the passage 8i bringing the fluid pressure into the confines 82 and causing the plungers 83 to be moved outwardly in turn forcing the extensions 91 from disengagement with the indentations 88 in the piston rod 99. When this is accomplished, the pressure will continue to build up and at the same time the air pressure will also be caused to branch off from the conduit 41 into the conduit 48 connected to the upper portion of the chamber 16 of the cylindrical element 49. The piston 53 therein will be caused to move downwardly. After it has moved down to the bottom into the portion 59 of the chamber in the element 49, the air in the conduit 48 and within the chamber of the element 49 will be directed to the passage 55, and thru the orifice 11, into the conduit 56. Conduit 56 being in communication with the conduit 99 leading up to the top of the opening in the cylinder or jack body 99 and immediately contiguous to the shoulder structure I25 will cause the air pressure to build up in there forcing the piston 94 in a downwardly direction, until the shoulder I24 touches the top of the element I9 I. Then the h passage-way comprised of the sections 93 and 9], inter-communicating by virtue of the interconnecting passage 92, will be brought in alignment with the confines of the chamber 92, vwhile the locking means 88 will be caused to engage the indentations 99 thus maintaining the piston in a downwardly locked position. The foot I95 will then be extended so that the gripper teeth I 96 will engage the surface of the support causing the load attached to the Jack structure to be raised above the supporting surface. The recessed portion I1I provides articulation and equalization for un-evenness of The air in the chamber portion 59 below the rack portion 53 will be vented thru conduit 5I in communicationwith chamber I22 and exhausted thru orifice H8.

When the piston is in the upward position prior to its movement downward, the air confined within the-cylinder 99 below the piston must be exhausted in order to permit the pressure above the piston entering the conduit 91 to be eifective. That is accomplished by the air within the chamber of the body 98 being causedto pass out and up thru the conduit 5.. When the valve H9 is in normal position, the outlet H5 is in communication with the conduit I I4 connected to the conduit H2, in turn connected to the .chamber III and to the enlarged area H9, in turn connected to the conduits 39 which are in communication 82. Hence when the piston is at its downward position, the passages 93 and 9| communicate with the conduit I I 6, that is, the passage 93 is in alignment with conduit II6, whereas the passage 9| communicates with the chamber 82 thus permitting the compressed air Within that chamber to be exhausted thru the conduit H6. The conduit II6 communicates with the conduit II4 which is connected'to passages II2, III, and H9 in section I99, and ultimately thru the conduit 39 to pass compressed air through the exhaust 3|. Air comes in thru the vent holes 86 and 85 respectively to relieve the potential energy of the compressed springs I12 to cause engagement of the locking means 81 with the indentations 99.

After work has been done on the load which had bee-n raised, for example, such as the chassis I5 in this particular instance, it is necessary now to retract and rotate angularly the jack structure in order to permit normal operation of the vehicle.

-In order to accomplish that, the fluid pressure I means is associated cooperatively with another virtue of electrical conductors I39, I49, 2| and 22.

This action permits the electric current to energize the solenoid 24, the core of which being integrally secured to the stem 21, will cause the valve heads 28 to move to the right compressing the spring 49, thus bringing'abollt communication of the fluid pressure means from the reservoir 38 thru the conduit I91. The conduit I91 being in turn connected thru the conduit 32 to the valve structure 29, by virtue of reduced body 39, furnishes communication between the conduits 32 and 39. The conduit 39 causes the air pressure to build up within the confines of the passagesv 1 the conduit H3 and also thru the conduit II4,

which is in communication with the conduits I I5 and H6, causing air pressure to come thru II 5 directly below the piston and simultaneously therewith causing air pressure to be built up thru the conduit I I6. The air pressure communicating thru the passages 93,92 and 9i into the confines 82, causes the locking pins 81 to be disengaged from the indentations 99 preparatory to retraction of the piston. The pressure then continues to build up thru conduit II5 causing the piston to return to the upward position, and at the same time causing the air above the piston to be evacuated thru the passage 91. The passage 91 communicating thru the passage 96 and thru the confines 69 of the valve structures 58 ultimately exhausts the air above the piston thru the orifice 59.

As soon as the piston has reached the top, and the pressure continues to build up within the confines of the conduits H6 and I I5, and since both said conduits are in communication with passage II4 by virtue of undercut I29, the spring I2I is further compressed by movement of plunger valve stem H9 in the chamber I22, ultimately causing the passage, I I5 to establish communication with the passage 5I. The passage 5I in turn communicates, thru the opening15, with the-bottom 59 of the chamber within the element 49, whereby the piston 52 is caused to move upweirdly, thus rotating the jack structure an angu- 11 lar or arcuate distance of 90". At this stage the retainer plunger II, by virtue of the cam structure I 11, is caused to be compressed and released, then brought to rest on the shoulder I of keeper means 69 The vent H8 permits free operation for valve H9.

The switches 23 are to beopen when the switch is is operated, and vice versa when the switch i9 is open the switches 23 are closed.

Before the angular, or arcuate movement of the jack to inoperative position, chambers 82 are vented through passages 18, 56, 11, 55, 54, l8, l1 and port 43. Thus the extensions 81 of the plungers 83 will be ready to engage the indentations 88 when the piston rod 99 is completely retracted to normal position. The air in chamber section 16 above the rack piston 53 is evacuated thru the vented means 43 in the valve 4|.

Tho, it has not been indicated, yet it is to be clearly understood that the piston and piston rod structure is to be keyed by a feather key arrangement to prevent rotation thereof as it is highly essential that the h passages remain in the same position for alignment, particularly with the conduits 18 and I I6.

Altho, I have, herein, elucidated in rather succinct terms the nature of the construction and operation of my electromagnetically controlled fluid pressure lifting jack mechanism, and inasmuch as, the same is susceptible of many modifications, alterations, and improvements, I hereby reserve the right to all such alterations, and improvements coming within the scope and spirit of my invention, or those embraced. suggestively or impliedly withinv the representation of the accompanying drawing, as well as those falling within the purview of the foregoing description: my invention to be limited only by the subjoined claims.

Having thus described and revealed my invention, what I claim as novel and desire to secure by Letters Patent, is:

1. A fluid jack mechanism comprising, a bracket secured to a load to be raised, a jack body articuiately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pin-' ion means secured within the said jack body and adapted to motivate the said Jack body thru an arcuate sector of substantially 90, a jack piston telescopically secured within the said jack body and adapted to "be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to thesaid load to be raised, retainer means secured to the said jack body adapted to engage releasabiy the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said jack piston to extended position,

respect thereto, piston locking means secured to the said jack'body and adapted to lock releasably the said jack piston in extended and retracted position, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage reieasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said jack piston to extended position, elective-magnetic valve means controllable remotely with respect to the said Jack body and adapted to control the passage of said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, and secondary valve means associated with the said jack body adapted to cause fluid pressure toinitially release the said piston locking means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation.

3. A fluid jack mechanism comprising, a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said Jack body thru an arcuate sector of substantially 90, a Jack piston telescopically secured within the said Jack body and adapted to'be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted position, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to en e releasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially disenage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means and ultimately to cause the accumulated fluid pressure to motivate the said jack piston to extended position, electro-magnetic valve means controllable remotely with respect to'the said jack valve means and to the said fluid operable rack and electro-magnetic valve means controllable remotely with respect to the said Jack body and and pinion means, secondary valve means associated with the said jack body adapted to cause fluid, pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the said jack piston. and thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle 01' operation, and secondary electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the fluid pressure from a source of supply to the said secondary valve means and to the said fluid operable rack and pinion means.

4. A fluid jack mechanism comprising, ,a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack. body thru an arcuate sector of substantially 90, a jack piston telescopically secured within the said jack body and adapted to be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted position, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said jack piston to extended position, electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the fluid pressure from a source of supply to the said valve means and to e the said fluid operable rack and pinion means, secondary valve means associated with the said Jack body adapted to cause fluid pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the saidpinion means, the said keeper means being pro- 7 a source of supply to the said .valve means and to the said fluid operable rack and pinion means.

rack means having one end thereof secured to the said equalizer foot support means, its other end being slidably secured to the outer portion of said jack body, and duplex pawl means articulately secured to the said jack body adapted to alternately engage the said'rack means to safetelescopically secured within the said jack body and adapted to be extended and retracted with respect thereto, equalizer foot support means secured to the terminus of the said jack piston,

' piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper control the passage of said fluid pressure from' a source of supply to the said valve means and to the said fluid operable rack and pinion means,

vided with cam means adapted to cause engagement automatically of the said retainer means with the said keeper means simultaneously with the completion of the cycle of operation.

5. A fluid jack mechanism comprising, a bracktelescopically secured within the said jack body and adapted to be extended and retracted with respect thereto, equalizer foot support means secured to the terminus of the said jack piston, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured'to the said load to be raised, retainer means secured to the said jack' body adapted to engage releasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to imtially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said jack piston to extended position, electromagnetic valve means controllable remotely, with respect to the said jack body and adapted to control the passage of said fluid pressure from secondary valve means associated with the said jack body adapted to cause fluid pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operabie rack and pinion means to normal position completing the cycle of operation, rack mean having one end thereof secured to the said equalizer foot support means, its other 'end being slidably secured to the outer portion of said Jack body, and duplex pawl means articulately secured to the said jack body adapted to alternately engage the said rack means to safeguard the load against damage upon failure of the fluid pressure system. V

7. A fluid jack mechanism comprising, a bracket secured to a load to be raised,a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially fluid operable rack and pinion means secured within the said jack body and adapted to motivate'the said jack body thru an arcuate sector of substantially 90, a lack piston telescopically secured within the said jack passing therethru to initially disengage the said 7 pressure to initially release the said piston looking means, secondly to cause fluid pressure to retract the said Jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, and secondary electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the passage of said fluid pressure from a source of supply to the damage upon failure of the fluid pressure system.

9. A fluid jack mechanism comprising, a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack body thru an said secondary valve means and to the said fluid v operable rack and pinion means.

8. A fluid jack mechanism comprising, a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion arcuate sector of substantially 90", a lack piston telescopically secured within the said jack body and adaptedto be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said piston in extended and retracted position, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimeans secured within the said jack body and adapted to motivate the said jack body thru an arcuate sector of substantially .90", a jack piston telescopically secured within the said jack body and adapted to be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and

- ultimately to cause the accumulated fluid pressure to motivate the said jack piston to extended position, electro-magnetic valve means controllable remotely with respect to the said lack body and adapted to control the fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated with the said jack body adapted to cause fluid pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, secondary electro-magnetic valve means controllable remotel with respect to the said Jack body and adapted to control the fluid pressure from a'source of supply to the said secondary valve means and to the said fluid operable rack and pinion means, the said keeper means being provided with cam means adapted to cause engagement automatically of the said retainer means with the said keeper means simultaneously with the completion of the cycle of operation, rack means having one end thereof secured to the said equalizer foot support means its other end being slidably the said jack body adapted to alternately engage the said rack means to safeguard the load against mately to cause the accumulated fluid pressure to motivate the said jack piston to extended position, electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the passage of said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and.

pinion means, and venting means provided within said jack body communicating with the said valve means to permit exhaustion of the air within the said Jack body.

10. A fluid jack mechanism comprising. a

bracket secured to a load to be raised, a jack respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially'disengage the said retainer means from the said keeper-means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately cause the accumulated fluid pressure to motivate the said jack piston to extended position, eiectro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the fluid pressure from a source or supply to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated with the said jack body adapted to cause fluid pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, venting means provided within the said jack body communicating with the said secondary valve means and the said electro-magnetic valve means to permit exhaustion of the air within the said jack body while the said jack piston is being motipiston telescopically i? vated to extended position, and secondary venting means provided within thesaid Jack bodycommunicating with the said first-mentioned valve means to permit exhaustion of the air within the said jack body while the said jack piston is being retracted to normal position.

11. A fluid jack mechanism comprising, a

tions, keeper means secured to the said load to be raised, retainer means secured to the said lack body adapted to engage releesably the said heeper means, valve means associated with the said jack body to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly, to cause the accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said Jack piston to extended position, electromagnetic valve means controllable remotely with respectto the said jack body and adapted to control the pas aseor said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated with the said jack body adapted to cause fluid pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the said lack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, secondary electromagnetic valve means controllable remotely with respect to the said jack body and adapted to control thepassage of said fluid pressure from a source of supply to the said secondary valve ineans and to the said fluid operable rack and pinion means, venting means provided within the said jack body communicating with the said secondary valve means and the said secondary electro-magnetic valve means to permit exhaustion of the air with in the said jack body while the said jack piston is being motivated to exmnded position, and secondary venting means provided within the said jack body communicating with the said first men tioned valve means to permit exhaustion of the air within the said jack body while the said jack piston is being retracted to normal position.

12. A fluid Jack mechanism comprising, a

bracket secured to a load to .be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinionmeans secured within the said jack body and adapted to motivate the said. jack body thru an arcuate sector of substantially 90, a, jock piston telescopically secured within the said jack body and adapted to be extended and retracted with respect thereto, piston locking means secured to the said Jack body and adapted to lockassent with the. said jack body adapted to causefluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said Jack piston to extended position, electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to' control the passing of said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated with the said jack body adapted to cause fluid pressure to initially release the said piston looking means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, secondary electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the passage of said fluid pressure from a source of supply to the said secondary valve means and to the said fluid'operable rack and pinion means, the said keeper means being provided with cam means adapted to cause engagement automatically of the said retainer means with the said keeper means simultaneously with the completion of the cycle of operation, venting means provided within the said Jack body communicating with the said secondary valve, means and the said secondary electromagnetic valve means to permit exhaustion of the air within the said jack body while the said jack piston is being motivated to extended position, and secondary venting means provided within the said Jack body communicating with the said first mentioned valve means to permit exhaustion of the air withinv the said jack body while the said Jack piston is being retracted to normal position.

13. A fluid Jack mechanism comprising, a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the saidjack body thru till an arcuate sector of substantially a jack piston telescopically ecured within the said jack body and adaptedto be extended and retracted with respect thereto, equalizer foot support means secured to the terminus of the said jack piston, piston locking means secured to the said Jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said jack piston in extended posireleasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated tion, electro-magnetic valve means controllable remotely with respect to the saidjack body and adapted to control the fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means,

rack means having one end thereof secured tothe said equalizer foot support means, its other end being slidably secured to the outer portion of said rack body, duplex pawl means articulately secured to the said jack body adapted to alternately engagethe said rack means to safeguard the load against damage upon failure of the fluid pressure system, venting means provided within the said jack body communicating with the said secondary valve means and the said secondary electro-magnetic valve means to permit exhaustion of the air within the said jack body while the said jack piston is being motivated to extended position, and secondary. venting means provided within the said jack body communicating with the said first mentioned valve means to permit exhaustion of the air within the said Jack body while the said jack piston is being retracted to normal position,

14. A fluid Jack mechanism comprising, a-

bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack body thru an arcuate sector of substantially 90, a jack piston telescopically secured within the said jack body and adapted to be extended and retracted with respect thereto, equalizer foot support means secured to the terminus of the said jack piston, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated with the said Jack body adapted to cause fluid pressure passing therethru to initially diseneaae the said retainer tially release the said piston locking means, sec

ondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, rack means having one end thereof secured to the said equalizer foot support means, its other end being slidably secured to the outer portion of said jack body, duplex pawl means articulately secured to the said jack body adapted to alternately engage the said rack means to safeguard the load against damage upon failure of the fluid pressure system, venting means provided within the said jack body communicating with the said secondary valve means and the said secondary electro-magnetic valve means to permit exhaustion of the air within the said Jack body while the said jack piston is being motivated to extended position. and secondary venting means provided within the said jack body communicating with the said first mentioned valve means to permit exhaustion of the air within the said lack body while the said 20 of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack body thru an arcuate sector of substantially 90", a Jack piston telescopically secured to the said jack body and adapted to be extended and retracted with the said jack piston in extended and retracted mately to cause the accumulated fluid pressure to 1 motivate the said jack piston to extended position, electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the passage of said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated with the said jack body adapted to cause fluid pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, secondary electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the fluid pressure from a source of sup ly to the said secondary valve means and to the said fluid operable rack and pinion means, venting means provided within the said jack body communicating with the said secondary valve means and the said secondary electro-magnetic valve means to permit exhaustion of the air within the said Jack body while the said jack piston is being motivated to extended position, and secondary venting means provided within the said Jack body communicating with the said first-mentioned valve means to permit exhaustion of the. air within the said jack body while the said jack piston is being retracted to normal position.

16. A fluid jack mechanism comprising, a bracket secured toa load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack body thru an arcuate sector of substantially 90, a jack piston telescopically secured within the said jack body and adapted to be extended and retracted with respect thereto, equalizer foot support means secured to the terminus of the said Jack piston, piston locking means secured to the said Jack body and adapted to lock releasably the said Jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said lack body adapted to engage releasably the said keeper means. valve means associated with the said lack body adapted to cause fluid pressure passing therethru tolnitially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston lockingmeans, and ultimately to cause the ac- -cumulated fluid pressure to motivate the said 18 lack piston to extended position, electro-mag- 21' netic valve means controllable remotely with respect tothe said jack body and adapted to control the passage of said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated with the said jack body adapted to cause fluid pressure to initially release the said piston locking means,secondly to cause fluid pressure to retract the said jackpiston,third- 1y to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, secondary electro-magnetic valve means controllable remotely with respect to the sai jack body and adapted to control the passage of said fluid pressure from a source of sup ply to the said secondary valve means and to the said fluid operable rack and pinion means, the said keeper means being provided with cam means adapted to cause engagement automatically of the said retainer means with the said keeper means simultaneously with the completion of the cycle of operation, rack means having one end thereof secured to the said equalizer foot support means, its other end being slidably secured to the outer portion of said jack body, duplex pawl means articulately secured to the said jack body adapted to alternately engage the said rack means to safeguard the load against damage upon failure of the fluid pressure system, venting means provided within the said jack body communicating with the said secondary valve means and th said electro-magnetic valve means to permit exhaustion of the air within the said jack body while the said jack piston is being motivated to extended position, and secondary venting means provided within the said jack body communicating with the said first mentioned valve means to permit exhaustion of the air within the said jack-body while the said jack piston is being retracted to normal position.

17. A fluid jack mechanism comprising, a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack body thru an arcuate sector of substantially 90, a jack piston. telescopically secured within the said jack body and adapted .to be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releasably the said keeper means, valve means associated with the said jack bodyadapted to cause fluid pressure passing therethru to initially disengage the said retainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said jack piston to extended position, el ctro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the passage of said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, and venting means provided within the said jack body and the said jack piston and communicating With the said piston locking means and the said valve means to permit exhaustion of fluid pressure freeing the. said piston locking means for engagement with the said jack piston.

18. A fluid Jack mechanism comprising, a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack body thru an arcuate sector of substantially 90, a jack piston telescopically secured within the said jack body and adaptedto be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said Jack body adapted to engage releasably the said keeper means, primary valve means associated with .the said Jack body adapted to cause fluid pressure passing therethru to initially disengage the saidretainer means from the said keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means and ultimately to cause the accumulated fluid tended position, electro-magnetic valve. means controllable remotely with respect to the said jack body and adapted to control the passage of said fluid pressure from a source of supply to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated with the said Jack body adapted to cause fluid pressure to initially release the said piston locking means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said'fluid operable rack and pinion means to normal position completing the cycle of operation, and venting means provided within the said jack body and the said jack piston and communicating with the said piston locking means and the said primary valve means to permit exhaustion of fluid pressure freeing the said piston locking means for engagement with 4 the said iackpiston.

19. A fluid Jack mechanism comprising, a bracket secured to a load to be raised, a jack body articulately secured to the said bracket and adapted to be motivated thru an arcuate sector of substantially 90, fluid operable rack and pinion means secured within the said jack body and adapted to motivate the said jack body thru an arcuate sector of substantially 90, a jack piston telescopically secured to the said jack body and adapted to be extended and retracted with respect thereto, piston locking means secured to the said jack body and adapted to lock releasably the said jack piston in extended and retracted positions, keeper means secured to the said load to be raised, retainer means secured to the said jack body adapted to engage releas-. ably the said keeper means, primary valve means associated with the said jack body adapted to cause fluid pressure passing therethru to initially 5 disengage the said retainer means from thesaid keeper means, secondly to cause accumulated fluid pressure to release the said piston locking means, and ultimately to cause the accumulated fluid pressure to motivate the said'jack piston to extended position, electro-magnetic valve means controllable remotely with respect to the said jack body and adapted to control the fluid pressure from a source of supp y to the said valve means and to the said fluid operable rack and pinion means, secondary valve means associated pressure to motivate the said Jack piston to ex-- with the said jack body adapted to cause fluid pressure to initially release the said piston lock ing means, secondly to cause fluid pressure to retract the said jack piston, thirdly to return the said fluid operable rack and pinion means to normal position completing the cycle of operation, secondary electro-magnetic valve means controllable remotely with respect to the said Jack body and adapted to control the fluid pressure from a source of supply to the said secondary valve means and to the said fluid operable rack and pinion means, and venting means provided within the said jack body and the said jack piston and communicating with the said piston locking means and the said primary valve means to permit exhaustion of fluid pressure freeing the said piston locking means for engagement with the said jack piston.

REFERENCES CITED UNITED STATES PATENTS Number Number Name Date Scott May 4, 1926 Smith Mar. 14, 1944 Goldman Dec. 15, 1931 Chavez et a1 Mar. 19, 1935 Campbell Mar. 4, 1941 Skavinsky Apr. 1, 1941 FOREIGN PATENTS Country Date Italy Nov, 24, 1931 

